The present invention relates to a single crystalline oxide superconductor and method of producing the same, in which a single crystal layer is formed over a substrate.
Recently, various oxide superconductors which exhibit very high critical temperatures (Tc) have been increasingly discovered. Various attempts have been made to coat a metallic substrate with superconductors by sputtering. However, such superconductors varied rather widely in critical temperature, and critical current density thereof was not sufficient.
The inventors have found that such drawbacks in physical properties were due to the crystal structure of superconductors. More specifically, oxide superconductors which are produced by sputtering are of multicrystals and are rather high in density of lattice defects, such as hole and dislocation, in each crystal grain.
It is an object of the present invention to provide a single crystal oxide superconductor and a method of producing the same which fairly reduces the drawbacks above mentioned.